This invention relates to the use of biomaterials for tissue repair and is particularly concerned with the use of physiologically acceptable polymeric materials in such tissue repair, especially cartilage repair.
The use of physiologically acceptable polymeric materials in the preparation of biomedical appliances such as hearing aids, artificial eyes and dentures is well Known, as is the use of polymeric materials as bone cements in the field of orthopaedics. Such polymeric materials are often used in the form of a curable composition which is initially in a fluid, semi-liquid, dough-like or other mouldable form, but which cures or hardens at the temperature of use to form a strong solid of physical properties dependent on the use to which it is being put. Examples of such curable compositions are to be found in International Patent Application No. WO89/03695 and GB Patent 2 107 341 which disclose the use of curable compositions comprising a powdered methacrylate polymer mixed with a methacrylate monomer. For such applications as the preparation of hearing aids, artificial eyes and dentures which require dimensional accuracy, it is important to provide compositions of low linear curing shrinkage and GB Patent 2 107 341 is directed to such an aim. For use as bone cement it is important to prevent subsequent failure at the bone-cement interface and, to this end, WO89/03695 discloses the inclusion of a cell growth stimulant such as human growth hormone so as to increase the rate of healing of, for example, a bone fracture and give a joint of increased strength. The emphasis in the previous use of these curable compositions has therefore been directed to attaining bonding strength and/or material strength and dimensional stability dependent on the intended use.